CIDR Calculator & Network Analyzer
Calculate CIDR blocks, subnets, and network information from IP addresses and subnet masks with comprehensive analysis.
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Calculate network details, subnets, and binary representations
CIDR Notation and Subnetting
CIDR (Classless Inter-Domain Routing) notation is a method for describing IP address ranges and subnet masks in a compact format. It uses a slash followed by a number to indicate how many bits of the IP address represent the network portion.
Understanding CIDR Notation
In CIDR notation like 192.168.1.0/24, the "/24" means the first 24 bits are the network portion, leaving 8 bits for host addresses. This creates a subnet with 256 total addresses (2^8), where 254 are usable for hosts (excluding network and broadcast addresses).
Key CIDR Concepts
- Network Address: The first address in the range, used to identify the network
- Broadcast Address: The last address in the range, used for broadcast communications
- Usable Host Range: All addresses between network and broadcast addresses
- Subnet Mask: Binary representation showing network vs. host portions
Common CIDR Blocks
- /8: 16,777,216 addresses (Class A equivalent)
- /16: 65,536 addresses (Class B equivalent)
- /24: 256 addresses (Class C equivalent)
- /30: 4 addresses (Point-to-point links)
- /32: 1 address (Host route)
This CIDR calculator helps network engineers plan and manage IP address allocations, calculate subnet ranges, and understand network boundaries for routing and security purposes.